1. Field of the Invention
This invention relates to biomaterial scaffolds, and more particularly to biomaterial scaffolds for intervertebral disc repair and/or regeneration and biomaterial scaffolds for articulating joint repair and/or regeneration.
2. Description of the Related Art
It is reported in U.S. Patent Application Publication No. 2003/0069718 and corresponding U.S. Pat. No. 7,174,282 that biomaterial scaffolds for tissue engineering perform three primary functions. The first is to provide a temporary function (stiffness, strength, diffusion, and permeability) in tissue defects. The second is to provide a sufficient connected porosity to enhance biofactor delivery, cell migration and regeneration of connected tissue. The third requirement is to guide tissue regeneration into an anatomic shape. It is further noted that the first two functions present conflicting design requirements. Specifically, increasing connected porosity to enhance cell migration and tissue regeneration decreases mechanical stiffness and strength, whereas decreasing porosity increases mechanical stiffness and strength but impedes cell migration and tissue regeneration.
U.S. 2003/0069718 provides a design methodology for creating biomaterial scaffolds with internal porous architectures that meet the need for mechanical stiffness and strength and the need for connected porosity for cell migration and tissue regeneration. The design methods of U.S. 2003/0069718 combine image-based design of pore structures with homogenization theory to compute effective physical property dependence on material microstructure. Optimization techniques are then used to compute the optimal pore geometry. The final optimized scaffold geometry voxel topology is then combined with a voxel data set describing the three dimensional anatomic scaffold shape which may be obtained by magnetic resonance (MR) images or combined MR and computed tomography (CT) images. Density variations within the anatomic scaffold voxel database are used as a map to guide where different optimized scaffold voxel topologies are substituted. The final voxel representation of the anatomically shaped scaffold with optimized interior architecture is then converted automatically by software into either a surface representation or wire frame representation for fabrication of the scaffold by way of solid free form fabrication or casting.
While the advances of U.S. 2003/0069718 have significantly improved the design of biomaterial scaffolds for tissue engineering, there is still a need for further advances in this technology to provide for even more optimized biomaterial scaffolding and tissue generation systems.